Generally, modular systems may utilize a backplane or midplane (hereafter the term of backplane is used for both a backplane or a midplane) in order to interconnect and organize a variety of modules (e.g., printed circuit boards or fans or power supply modules or other) within the modular system. For example, a backplane may be utilized in order to interconnect various functional modules such as blades to each other, to other chassis, and to external networks. Some backplanes may connect and organize the modules in a horizontal fashion, with each module connected to the backplane horizontally, while other backplanes may connect the modules in a vertical fashion. Additionally, other types of backplanes, such as an orthogonal backplane, may have a combination of connections, with some modules connected to the backplane horizontally and other modules connected to the backplane vertically.
However, while the orthogonal backplane configurations may have certain benefits, they also have certain drawbacks. For example, by having an orthogonal backplane configuration in which some modules are positioned vertically on one side of the backplane and other modules are positioned horizontally on another side of the backplane, cooling can become a major issue. In particular, the backplane and modules arranged in the orthogonal configuration create a complicated structure where a simple air flow over the modules is broken up by the various components and the backplane. This may become an even larger problem as processing and data transfer speeds continue their increases in speeds and heat generation.
FIG. 6A illustrates one attempt to cool an orthogonal backplane and its associated modules, as described in U.S. Pat. No. 7,826,222 (the “'222 Patent”) to Aybay, et. al. As shown in FIG. 6A (which is a reprint of the '222 Patent's FIG. 10), this patent describes horizontal modules connected to a backplane and located in a front of a chassis along with vertical modules connected to the backplane and located in a back of the chassis. As shown in FIG. 6A, cooling air is pulled from a front of the chassis and over the horizontal modules, through radial blowers, and out the rear of the chassis. Similarly shown in FIG. 6B (which is a reprint of the '222 Patent's FIG. 11), to cool the horizontal modules, cooling air is pulled in at the top of the front of the chassis, pulled across the top of the chassis to bypass the horizontal modules, induced by horizontal fans trays to pass over the vertical modules to provide cooling to the vertical modules before the cooling air is expelled out of the chassis at the back bottom of the chassis.